With a cleaning device to remove dust and dirt on a surface to be cleaned such as a floor surface with a cleaning device body to which a cleaning sheet made of non-woven fabric or the like as covering a cleaning surface, cleaning can be readily performed while dust and dirt are stuck to the cleaning sheet by wiping the surface to be cleaned with holding a handle portion attached to the cleaning device body by hand.
According to such a cleaning device, when a lower face of the cleaning device body to be the cleaning surface is simply a flat surface, it becomes difficult to wipe the surface to be cleaned with the entire cleaning surface as dust and dirt being easily stuck to a circumferential section of the cleaning surface. Accordingly, various types of cleaning devices having improved cleaning efficiency have been developed by devising a shape of a cleaning surface of a cleaning device body (e.g., refer to Patent Literature 1 and Patent Literature 2).
Further, as a cleaning device to perform cleaning of a floor surface, there have been known various cleaning devices respectively including a cleaning head to which a mop, a cleaning sheet or the like is attached and a handle which is rotatably joined to an upper face of the cleaning head via a joint portion. It is common for these cleaning devices that the handle is capable of performing a 360-degree rotation in the circumferential direction about the joint portion as well as the handle is rotated in the up-down direction against the cleaning head. Accordingly, cleaning of a floor surface and the like can be effectively performed while the cleaning surface of the cleaning head is oriented in an arbitrary direction (e.g., refer to Patent Literature 3).
Further, as a handle of such a cleaning device, there has been developed that a plurality of cylindrical pipes are integrated and joined in the axial direction with a pipe joint structure in which a male-side end portion of one cylindrical pipe is inserted to a female-side end portion of the other cylindrical pipe, an engaging projection is engaged from the outside after a male-side projection insertion hole and a female-side projection insertion hole are matched, and a sleeve-like member is attached as covering a joint line portion between the male-side end portion and the female-side end portion from the outside (e.g., refer to Patent Literature 4).
Further, as the structure of the joint portion enabling the handle to be rotated in the circumferential direction as well as the up-down direction, there has been generally known a structure in which a bifurcated head-side yoke portion arranged at an upper face center section of the cleaning head and a bifurcated handle-side yoke portion arranged at a lower end part of the handle are joined via a joint member including a first rotational axial center portion and a second rotational axial center portion of which center axes are orthogonal, for example (e.g., refer to Patent Literature 3).
Further, as a cleaning device to remove dust and dirt as wiping a floor surface, there has been popularly used a cleaning device in which a handle having length on the order of 100 to 150 cm, for example, being suitable for performing cleaning operation while standing is joined to a cleaning device body with a mop or the like.
Further, there has been known a cleaning device capable of being easily hanged in which an end cap made of synthetic resin is attached to an end part of a handle so as to prevent a cleaning device body from being damaged and to be capable of being stored in a stable state as being hanged to a hook member arranged at a wall surface or the like when not in use (e.g., refer to Patent Literature 5).
Further, as a cleaning device to perform cleaning of a floor surface, there have been known various cleaning devices respectively including a cleaning head to which a disposable cleaning sheet is attached to be replaceable in a detachably attached manner and a handle which is rotatably joined to an upper face of the cleaning head via a joint portion. In such a cleaning device, a cleaning sheet attachment made of soft elastic material with an engagement slit is arranged at four locations as being adjacent to each corner section of the rectangular cleaning head. The cleaning sheet can be easily attached to the cleaning head to be replaceable in a detachably attachable manner by performing attaching as squeezing end parts of the cleaning sheets into the slits of the cleaning sheet attachments at the upper face of the cleaning head after the cleaning sheet is wound to the cleaning head as covering a bottom face of the cleaning head from the lower side (e.g., refer to Patent Literature 7).
Further, there has been developed a cleaning device which prevents a cleaning sheet from being easily detached from a cleaning head during cleaning as improving attaching characteristics of the cleaning sheet attached as being squeezed into a sheet attachment (e.g., refer to Patent Literature 8). In the cleaning device of Patent Literature 8, each engagement slit arranged at the cleaning sheet attachment made of soft elastic material includes a holding slit formed into a saw-tooth shape as being extended in a direction at a right angle against a direction of tension force acting on the cleaning sheet and a plurality of opening slits extended continuously and radially from a center section of the holding slit. Then, end parts of the cleaning sheet are attached to the saw-tooth-shaped holding slits, so that the cleaning sheet can be reliably held after attached.